Note: Descriptions are shown in the official language in which they were submitted.
86~i
Removing fluids and air from the chest cavity while preventing
air from re-entering is an old and well-practiced technique. Under
emergency conditlons and perhaps at other times where nothing else is
available, things like vaseline-coated gauze are used over an open chest
wound. Under similar circumstances, one-way flaps made of rubber or
plastic have been used for this same purpose along with other contrivances
too numerous to mention.
Somewhat, but not a great deal, more sophisticated mechanisms are
generally used under controlled conditions-such as those which exist in the
operating room while performing chest surgery. The simplest of these
mechanisms is a so-called "water seal" which is nothing more than a bottle
to receive the drained fluids and air that is partially filled with sterile
water, saline or the drained fluids themselves that has the chest drainage
tube from the patient opening beneath the surface of this body of fluid so
that the air cannot return by the same route. Such a trap was, and to some
extent still is, used with a fluid collection bottle serially connected to
the latter but upstream thereof.
The next degree of sophistication added many years ago to the
two-bottle chest drainage system described above was a third bottle, again
connected serially to the other two, but this time downstream thereof.
This third bottle served the function of regulating the vacuum impressed
upon the patient's pleural cavity to suck the fluids and air therefrom. It
included a tube open to the atmosphere at one end and with the other end
opening a preset distance below the level of a supply of fluid contained
therein. Functionally, at such time as the negative pressure in the system
reached the predetermined level established by the head of fluid above the
underwater inlet to the pressure-equalizing tube, it would suck in air from
7T~
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~17~866
the atmosphere. In this way the patient was protected against negative
pressures being impressed upon his or her chest cavity that exceeded a
preset level. This three-bottle system did not, however, measure the
negative pressure to which the patient's chest cavity was subjected. It
only placed an upper limit thereon. Thus, with a three-bottle system, the
patient is fully protected even if the suction pump fails in the open state
or the vacuum line becomes accidently disconnected.
The fourth and final bottle added to the three-bottle system
included a vent operative to relieve pressure therein at such time as it
rose to a predetermined level. Excessive pressure build-up can occur if,
for example, the vacuum pump were to fail in the closed state or the tube
leading thereto becomes obstructed and the patient has an active air leak~
Under such circumstances, a positive pressure can build up in the patient's
pleural cavity leading to what is known as "tension pneumothrax" which can
and often does have fatal consequences.
The prior art patented chest drainage bottles are, so far as
applicant is aware, all owned by Deknatel, Inc. of Queens Village, Long
Island, New York. Specifically, applicant is aware of their ~.S. Patent
Nos. 3,363,627; 3,559,647; and, 3,683,913, all of which relate to some form
of multi-compartmented chest drainage apparatus. All three of these
patents disclose bottles with a plurality of fluid-filled chambers therein,
at least one of which forms the traditional water seal of the prior art
two, three and four bottle systems while a second defines an underwater
safety seal that prevents the build-up of positive presence above a
predetermined value.
The aforementioned Deknatel chest drainage bottles are in
widespread use today throughout the ~nited States and elsewhere and they
,~
,
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1~7~866
perform well in collecting fluids drained from the chest cavity while, at
the same time, protecting the latter from excessively high pressures, both
positive and negative. These units do, however, have one serious drawback
and that is the necessity for priming them before use. In fact, even
during use they must be reprimed at intervals because of evaporation which
lowers the fluid levels therein and thus changes the pressures at which the
"fail-safe" features are designed to function.
It has now been found in accordance with the teachin~ of the
instant invention that this and other shortcomings of the prior art chest
drainage systems can be overcome by the simple, yet unobvious, expedient of
eliminating all underwater seals and pressure regulating systems predicated
upon fluid head and replacing them with suitable fluidless valve mechanisms
that provide accurate pressure regulation, both positive and negative,
along with foolproof reverse flow protection. In addition, the instant
system not only provides for negative pressure regulation but, in addition,
the continuous monitoring thereof. An incidental, but nonetheless
important, advantage of the system that needs no priming is the fact that
the fluid-filled bottle can be used as a reservoir for returning the fluids
collected to the patient's chest cavity, a function that the prior art
chest drainage bottles cannot perform. Yet another feature of the instant
system which finds no counterpart in the prior art is a transparent
fluid-filled U-tube indicator that not only surges back and forth in
response to the inhalations and exhalations of the patient but, in
addition, provides the observer with a visual indication of any air flowing
in the system. Last, but by no means least, is the novel construction
wherein all the precision elements of the drainage apparatus are confined
to one small detachable subassembly and a poppet-type pressure
relief valve thus enabling the fluid collection bottle a relatively
1~7~86~
imprecise element that can be fabricated by high volume, low cost mass
production techniques without adversely affecting the overall precision of
the system.
It is, therefore, the principal object of the present invention
to provide a novel and improved chest drainage apparstus.
A second objective is the provision of apparatus of the type
aforementioned which requires no priming, either initially or during use.
Another object of the within described apparatus is that of
providing a low precision fluid collection bottle and a high precision
subassembly for use therewith which, along, with a poppet-type pressure
relief valve, all cooperate to produce a system possessing, for all
practical purposes, the same high degree of precision as its most precise
part.
Still another objective is the provision of a chest drainage
system wherein the fluid collection bottle that forms an integral part
thereof can be used as a reservoir for returning the fluids collected to
the chest cavity by merely disconnecting and re ving one detachable
subassembly therefrom and shutting off the drainage tube.
An additional object is to provide an apparatus of the type
herein disclosed and claimed for draining the chest cavity which provides a
visual indication of any air flow in the system and, in addition, monitors
the negative pressure.
Further objects are to provide a chest drainage apparatus which
is safe, relatively inexpensive to manufacture, simpler than the prior art
multi-chambered chest drainage bottles, is convenient to use, versatile,
; compact, lightweight and even decorative.
1~7(~H6~
1 Broadly stated, the.inventiqn is a non-waterseal thoracic
2 drainage apparatus comprising: means defining a fluid cotlect;on chamber
3 with an air space thereabove; means defining an air chamber connected to
4 receive.air from the air space above the fluid collection chamber; means
comprising a one-way waterless valve means interposed between said air space
6 and air chamber, said waterless valve means being opera~ive to admit air
7 to said air chamber while preventing reverse flow back into the collection
8 chamber; said one-way waterless valve means being operative to prevent said
9 reverse flow unaided by underwater seals; an inlet tube in communication
0 with the fluid collection chamber and be;ng connectable to receive fluids
1l and air from a patient's chest cavity to be drained and to deliver same
12 to the fluid collection chamber; means defining a flow path between the
3 inlet tube and said one-way waterless valve, a portion of said fluid flow
4 path defining a U-shaped path; said portion of the U-shaped fluid path being
constructed so as to be transparent, said U-shaped portion of flow path
16 being adapted to retain a measure of fluid so as to cooperate to provide a
17 visual indication of any air passing therethrough and of oscillations in the
18 patient's breathing.
19 In another aspect, the invention comprises a subassembly for
use with a thoracic drainage bottle, said bottle containing a fluid
21 collection chamber w;th an air space therabove~ the bottle having an inlet
22 adapted to be connected to the chest cavity of a patient for receiving
23 fluid and air therefrom and del.ivering same to said collection chamber,
24 the bottle having an outlet communicating with the air space, said air
space and outlet defining an air flow path. The subassembly comprises means
26 defining an air chamber having an inlet adapted to receive air from the
27 outlet of the bottle, one-way waterless valve means disposed along said
28 flow path, said waterless valve means being automatically operatiVe to
29 admit air to said air chamber while preventing reverse flow back into the
bottle, and relief valve means for enabling venting of the air space, said
31 relief valve means being automatically operative to open and relieve the
32 pressure in said air space when said pressure rises above the predetermined
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`i.~7~61Ei
1 level, said one-way waterless valve.being operative to prevent said
2 reverse flow unaided by underwater seals, whereby said subasse~bly may
3 control operation of the flow direction in said drainage syste~.and
4 maintain a controlled pressure.range therein without requ.iring the use of
an underwater seal.
.,
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~17~3866
Other objects will be in part apparent and in part pointed out
specifically hereinafter in connection with the description of the drawings
that follows, and in which:
Fig. 1 is a front elevation, portions of which have been broken
away and shown in section, revealing the chest drainage apparatus of the
present invention in its entirety;
Fig. 2 is a horizontal section therethrough taken along line 2--2
of Fig. l;
Fig. 3 is a fragmentary section to the same scale as Fig. 1
showing the high negative pressure relief system of the apparatus in
operation;
Fig. 4 is a fragmentary vertically offset section taken along
line 4--4 of Fig. 1 and to the same scale as the latter; and,
Fig. 5 is an elevational view, portions of which have been broken
away and shown in section, to a slightly smaller scale than Fig. 1.
3866
Referring next to the drawings for a detailed description of the
present invention and, initially, to Fig. 1 for this purpose, reference
numeral 8 broadly designates the chest drainage apparatus in its entirety
while numerals 10 and 12 similarly designate the bottle and the control
subassembly, respectively. Subassembly 12 is detachably connectable to the
bottle and it includes a check valve 14, a positive pressure relief valve
16 and a control valve 18 that regulates the negative pressure in the
system. Another element forming a part of subassembly 12 and which will
be described in greater detail presently is a negative pressure gauge 24
that also opens onto the interior of air chamber 20.
Bottle 10, in the particular form illustrated in Figs. 1 and 2
will be seen to comprise a unitary blow-molded reservoir defining, among
other things, a series of three fluid collection chambers 26A, 26B
and 26C separated from one another by partitions 28A and 28B that each
contains openings 30A and 30B, respectively, near the top thereof that
permit the chest drainage fluids to pass freely from the first to the
second when the first is full and from the second to the third when both of
the first two are f ull. These partitions 28 are shown as being double
walled and also having an integrally-formed web 32 bridging the gap left
between the double walls. This same web extends along the bottom of the
bottle and across the top except for the noeched-out portion 34 into which
subassembly 12 is inserted. Vertically-slotted clips 36 on opposite ends
of subassembly 12 slide down the opposed margins 38 of web 32 that border
the sides of notch 34 thus detachably-mounting subassembly 12 within the
confines of the latter. When thus mounted, tubular air inlet 40 opening
into the bottom of air chamber 20 through check valve 14 will be axially
aligned with the air outlet 42 in the top of bottle 10, A short hose
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117~866
connection 44 completes the air connection between bottle 10 and the air
chamber 20 of subassembly 12.
The bottle is molded from a transparent material that will show
the level of the fluid in any of the fluid chambers 26. Each of these
three chambers has the front face thereof covered by an adhesive-backed
paper label 46 or other suitable scale-carrying member having a vertical
slot 48 therein through which the fluid level is visible. The label has
printed upon its surface a volumetric scale 50 indicating the total volume
of fluid stored at the liquid level visible through slot 48 in the last of
the chambers containing fluid. For instance, chamber 26A of the particular
bottle illustrated will hold a maximum of 700 cc's of fluid before
overflowing into second chamber 26B. This second chamber, in like manner,
will hold another 700 cc's even though it can only fill to the level of
partition 28B before spilling over into the third chamber 26C. While
chamber 26B fills to a level lower than 26A, it holds the same amount due
to the truncated corner 52 of the latter. The third chamber 26C is
similarly truncated and is designed to fill to the same level as chamber
26B and thus holds less than the other two, specifically, 600 cc's giving a
total fluid storage capacity of 2000 cc's. The paper label also provides
the nurse with a convenient way of recording thereon the fluid level in the
bottle at any observed time.
While on the sub~ect of fluid storage capacity, reference should
be made to Figs. 1, 2 and 5, and note should be taken of recess 54 in the
back wall of chamber 26A which has an opening 56 at its deepest point
sealed by a puncturable grommet 58. If perchance, the bottle is filled to
near full capacity, a sterile needle (not shown) can be introduced into
chamber 26A through conventional resealable grom~et 58 and used to withdraw
a considerable quantity of the fluid contained therein thus extending the
~7~866
norma] maximum capacity of the bottle. Instances also are encountered
occasionally where the capacity of the bottle is too large such as when
draining fluid from the chest cavity of an infant or small child. Under
such circumstances, it may be desirable to introduce fluid int~ one or more
of the chambers in the form of sterile water or saline. Grom~et 58,
therefore, can serve either the functions of infusion or withdrawal of
fluids from the bottle. The recessed relation of the grommet makes it
easier to keep clean and free of contaminants that might otherwise find
their way into the bottle when the grommet is entered.
From a functional standpoint, the three serially-connected
chambers 26A, B and C are the full equivalent of a single thin chamber
three times as deep because both provide precise volume control
unattainable with a single shallow chamber of the same capacity. The
space-saving advantages of the side-by-side multiple chamber configuration
are obvious as are the equally significant gains in terms of simplicity of
manufacture. It should be emphasized, however, that these three chambers
26 are used exclusively as reservoirs for the storage of fluid and they
have no other function whatsoever; whereas, the prior art multi-compartment
bottles each have one or more compartments that must be primed with water
which changes their character from that of pure fluid storage vessels to
something else. The bottle lO of the instant chest drainage assembly,
therefore, requires little in the way of precision and is thus intended to
be disposed of following a single use or repeated use by the same patient.
All the precision-made parts of assembly 8 are confined to subassembly 12
with the exception of negative pressure relief valve 60 which is of the
conventional poppet-type except that it contains a bacterial filter.
The novel aspects of the bottle lO are not found in the fluid
collection chambers 26, but rather, in such unique features as transparent
_ g _
117~866
U-tube 62 formed at the entrance to the fluid collection and storage area
defined by compartments 26. The entrance 64 to this U-tube is also the
single fluid inlet to the system and it is connected directly to the
patient's chest cavity by drainage tube 66. In the particular form shown
in Fig. 1, a fluid-tight two-part combination connector and coupling of
standard design 68 is interposed between the discharge end of the drainage
tube and the inlet 64 to the bottle.
Referring specifically, once again, to Fig. 1, it can be seen
that a small volume of fluid 70 will be trapped within the bend in U-tube
62 once fluid begins flowing from the patient. While this U-tube could be
primed with a few cc's of sterile water or saline through puncturable
grommet 72 disposed near the low point thereof, priming is unnecessary
because, in a sense, it is self-priming once fluid begins to flow from the
chest cavity. As was the case with grommet 58, grommet 72 can also be used
for the purpose of aspirating or otherwise withdrawing a sample of drained
fluid to be cultured.
- The fluid 70 contained within U-tube 62 is not a water seal
effective to prevent the return of air to the patient and, as a matter of
fact, the-chest drainage assembly of the present invention will perform
2~ quite adequately whèther there is any fluid in the U-tube or not and
irrespective of its level. This is not to say, however, that the fluid
filled U-tube has no function. On the contrary, it performs two very
significant ones, namely, as botb an air leak detector and an indicator of
the inhalations and exhalations of the patient~as it fluctuates and
alternately rises higher;in one leg of the U-tube than the other. As the
small amount of fl~id in the U-tube thus oscillates back and forth under
the influence of the differences in pressure caused by the patient's
breathing pattern, it provides a clear visual indication that the patient
is, in fact, breathing. .;
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l.t~866
The other important functional aspect of U-tube 62 is that of
providing a leak detector effective to provide the observer with an instant
visual indication of either an air leak in the system or the more serious
consequence of an air leak originating in the patient's chest. If, perchance,
air bubbles are detected bubbling in a downstream direction through the fluid
in the U-tube, the drainage tube 66 should not be either clamped off or
removed from the patient until the source of the leak is located. Other than
a system leak, the source of air entering bottle 10 comes either from air
leaking from the patient's lungs or, alternatively, from air displaced from
the chest cavity by the draining fluid.
The sole function of the so-called water seals in the prior art
chest drainage systems is that of preventing the backflow of air into the
patient's chest cavity. Such systems must be primed before the water seal
becomes operative as previously noted. In the instant chest drainage system,
on the other hand, no such fluid seal is present because the fluid in U-tube
is fully capable of passing air in either direction, i.e. back into the
patient as well as out. Instead, a high precision flapper-type check
valve 16 located at the interface between fluid collection chambers 76 and
the air chamber 20 of subassembly 12 answers this need. Valve 16 responds to
an opening pressure of approximately 0.5 cm H2O in the particular embodiment
illustrated and it functions completely independent of any fluid present in
either the fluid collection chambers or the ~-tube.
The full line position of Fig. 1 is the normal operating condition
of the system, assuming some air is being evacuated from the patient's chest
cavity. Fluids, mostly blood, enter the system through drainage tube 66 when
they are collected in chambers 26 after having passed through the U-tube. The
air, in turn, while passing through the fluid in the U-tube, bypasses any
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1~7~866
fluid collected in the fluid collection chambers and, instead, exits the
latter through check valve 14 directly nto air chamber 20. Under normal
operating conditions, a negative pressure environment will exist in
chamber 20 due to the vacuum being drawn therein by vacuum line 22 or,
alternatively, this line may be left open to the atmosphere for gravity
operation. Positive pressure relief valve 16 in the top of chamber 20
will normally remain closed. When maintaining a sub-atmospheric pressure
in chamber 20, the fluids and air are aspirated from the patient without
he or she having to exert the positive pressure required to force them
out.
Vacuum line 22 is connected directly into a vacuum source
supplied by the institution. Since such systems provide negative pressures
of a magnitude well in excess of that required for chest drainage purposes,
the outlet 74 thereto leading out of air chamber 20 is provided with a
screw-type pressure regulator 18 operative to control the pressure within
the latter and thus the opening pressure of check valve 16 within carefully
controlled rather narrow limits.
Now, in the rare event that a malfunction occurs of the type that
would result in a positive pressure build-up in air chamber 20, such a
happenstance having been indicated by the kinking of the vacuum line 22
shown in phantom lines in Fig. 1, the remote possibility arises that such a
positive pressure could blow out check valve 16 thus releasing this
pressure back into the chest cavity of the patient with the attendant
serious consequences. To prevent this from ever happening, positive
25 pressure relief valve 14 is provided in subassembly 12 for the purpose of
venting any positive pressure above a predetermined value to the atmosphere
before it can re-enter the system. Valve 14 like valve 16 is of the
- 12 -
.
1~7~86~
flapper type and set to open at a pressure well below that where valve 14
would be over-ridden and allow air back into the system. The phantom line
positions of valves 14 and 16 represent the abnormal positive pressure
relief condition just described. It should, perhaps, be noted that the
open positions of both these valves have been highly exaggerated in Fig. l
for purposes of illustration since they actually have to only unseat a tiny
fraction of an inch to accomplish their intended functions.
One of the most significant and unique features of ~he chest
drainage system forming the subject matter hereof is the negative pressure
indicator identified by reference numeral 24 and which forms an integral
and functional part of subassembly 20 and which has been shown most clearly
in Figs. l and 3 to which detailed reference will now be made. A
vertically-disposed upwardly-flaring frustoconical tube 76 opens into the
bottom of the air chamber 20 through restricted opening 78 therein, such
opening being too small to pass ball 80. A second opening 82 is provided
in the small truncated end of tube 76 which, likewise, is sized smaller
than ball 80. Opening 82 defines a controlled orifice open to the
atmosphere into which air is aspirated at a velocity sufficient to lift
ball 80 depending upon the magnitude of the negative pressure gradient
thereacross. The outside of tube 76 is provided with scale-forming indicia
84 reading directly in negative pressure measured in cm H20 or some other
suitable set of values.
Now, while floating ball-type indica~tors of the same general type
as that just described have been used for many years to indicate flow rates
in a flowing fluid, to applicant~s knowledge no such indicator has been
- used heretofore to read negative Rressures existent in the air chamber of a
chest drainage system. When so used, the attending physician and others
'
.
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il'7:~866
responsible for the safety and well being of the patient are provided with
an easily readable pressure gauge constantly monitoring the negative
pressure within chamber 20. Having thus described the fail-safe system
that becomes functional whenever a positive pressure above a predetermined
level is present in air chamber 20, a similar system will next be set forth
which responds in like manner to handle abnormal negative pressures within
the system for which purpose detailed reference will be made to Fig. 3.
Excess negative pressures are rare but could, conceivably, result
from a so-called "milking" or stripping of chest drainage tube 66. If this
should occur or if for some other reason an abnormal negative pressure is
present in air chamber 20, such a condition will immediately exist in the
fluid collection chambers 26 as well. If the negative pressure condition
occurs upstream of the system, the fluid in U-tube 20 would be sucked out
into the discharge tube and ultimately back into the patient's chest cavity
if it were not for the presence of negative pressure relief valve 60.
Likewise, if a sudden high negative pressure were to occur in air cha~ber
20 for some reason, relief valve 16 will be closed and check valve 14 will
be open exposing the fluid collection chambers 26 and everything upstream
thereof including the patient to this abnormal condition. With the instant
system, relief valve 60 connected into the fluid free air space 86 above
the fluid contained within the fluid collection chambers 26 will respond by
opening as illustrated to admit air from the atmosphere thus limiting the
maximum negative pressure thae can exist in the system to a predetermined
level well below that where any backflow to the patient can take place.
Negative pressure relief valve 60 is of the more or less common
poppet-type except that it incorporates bacterial filter 88 (Fig. 3)
which filters the incoming air to prevent contamination of the fluids
117~
stored in the fluid collection chambers. Valve 60 is detachably connected
to neck 90 of the bottle by means of a short length of hose 92 in the
particular form shown. The particular system illustrated has valve 60 set
to open at a maximum negative pressure of -50 cm H20 which has proven
entirely adequate to protect the patient. Once again, the accuracy
necessary for precise controlled operation of the system is found in valve
60 and is not demanded of throw away bottle 10 which merely provides a
connection 90 open to the atmopshere upon which to attach same. Fig. 3
illustràtes diagrammatically the condition described above where an
- excessive negative pressure is sensed in air chamber 20 that causes the
valve element 94 of valve 60 to move off its apertured seat 96 in
opposition to the bias of spring 98 and thus open to maintain the system
pressure at a maximum of -50 cm H2O.
In closing, reference will be made to Fig. 5 wherein a unique
capability of the instant bottle 10 has been illustrated, namelyj the use
thereof in inverted position as a reservoir to return the previously
drained chest fluids back into the patient's chest cavity. Without having
to transfer these fluids or otherwise handle them with the attendant risk
of contamination, drainage hose 66 is clamped off by clamp 100, subassembly
12 removed and a fluid delivery tube 102 fitted in its place to air outlet
42. Valve 60 need not be removed since it will remain in its
normally-closed condition. After tube102has been inserted into the
patient's chest cavity, the bottle can be inverted to dispense the fluids
stored therein by gravity flow. No other chest drainage system to
applicant's knowledge has a bottle that can be used in this way.
